A hole in the heart is never a good thing, so when an infant is born with such a defect, doctors have to act quickly to fix it. Unfortunately, both sutures and staples can damage the heart tissue, plus it takes too long to apply sutures. Existing surgical adhesives have their own drawbacks in that they can be toxic, and they typically become unstuck in wet, dynamic environments such as the heart. As a result, infants often require subsequent operations to "replug" the hole. Now, however, scientists have developed a sort of superglue for the heart, that quickly and securely bonds patches to holes.
Officially known as hydrophobic light-activated adhesive (HLAA), the glue was developed in a collaboration between Boston Children's Hospital, MIT, and Harvard-affiliated Brigham and Women's Hospital. It was inspired by the viscous, water-repellant fluids secreted by animals such as slugs.
The liquid glue, along with possessing those same characteristics, is also biocompatible, biodegradable, and has an elastic consistency once set. This combination of qualities means that it will remain adhered to the heart despite being immersed in liquid blood, it won't be rejected, it won't get pulled loose or ripped by the contractions of the heart muscle, and it will harmlessly biodegrade once the hole has healed over.
Additionally, HLAA sets in just five seconds, but only once it's exposed to an ultraviolet light source. What's more, because no stitching or stapling is required, procedures for applying patches treated with the glue should be considerably less invasive than the alternatives.
A close look at how the collagen in the heart tissue bonds with HLAA (Image: Pedro del Nido, Boston Children's Hospital)
In lab tests, biodegradable patches were coated on one side with HLAA, then applied to holes in the hearts of live pigs. Despite the high pressure of the blood flowing through the organs, the patches maintained a leakproof seal for the 24-hour test period. Interestingly enough, one of the lead scientists, Brigham and Women's Dr. Jeffrey Karp, is also the co-developer of surgical patches inspired by porcupine quills.
HLAA is now being commercially developed by Paris-based start-up Gecko Biomedical, which hopes to have it on the market within two to three years. The technology could potentially be applied not just to congenital heart defects, but to a wide variety of organs and other body parts.
A paper on the research was published this week in the journal Science Translational Medicine.